The effect of grape seed extract (GSE) feed supplementation on performance, antioxidant enzyme activity, and immune responses in broiler chickens suffering from heat stress were investigated in this study. Experimental diets including control diet (with no additive), 3 levels of GSE (150, 300, 450 mg/kg), and one level of vitamin C (300 mg/kg) as a positive control were fed to the birds from 1 to 42 d of age. The chronic heat stress (34±1 ˚C temperature for 5 hours per day) was provided from 29 to 42 d of age. The GSE supplementation up to 300 mg/kg diet increased the average daily gain of broiler chickens compared to the control group prior to heat stress (1-28 d). During the heat stress condition, dietary GSE at the rate of 300 and 450 mg/kg diet improved feed conversion ratio. The GSE supplementation at 300 mg/kg diet increased IgG titer as a primary and secondary response to sheep red blood cell (SRBC) injection. In addition, birds fed diet with GSE (150, 300, 450 mg/kg diet), or vitamin C (300 mg/kg diet) had higher levels of IgG titers as a secondary responses to SRBC. The GSE supplementation at the rate of 300 and 450 mg/kg diet reduced heterophil percent, heterophil/lymphocyte ratio, and increased the percentage of lymphocyte of broilers under heat stress. Supplementation of diet with GSE (300, 450 mg/kg diet) increased glutathione peroxidase (GPx) activity in birds under heat stress condition. The GSE or vitamin C supplementation did not affect the results of cutaneous basophil hypersensitivity (CBH) response, and relative weights of spleen and bursa of fabricius in chickens under heat stress. However, supplementation of diet with GSE (300, 450 mg/kg diet) or vitamin C (300 mg/kg diet) increased relative weight of thymus in birds under heat stress condition. Thus, GSE supplementation could alleviate the detrimental effects of heat stress in broiler chickens better than vitamin C and it is preferable for the health and economic goals since it is a natural waste by-product. تفاصيل المقالة

An experiment has been conducted to evaluate the effects of a liquid prebiotic (LP) on the carcass, digestive tract, and productive traits of Japanese quail. Eighty 7-day-old Japanese quails were randomly divided into 2 treatments. Each treatment consisted of 4 replicates (pens) of 10 birds each. The first treatment (control) contained a standard recommended diet with no added prebiotic. The second treatment was similar to the first diet accompanied by LP in the drinking water (0.5 milliliter LP per liter of water through the entire study). Feed and water were offered ad libitum from days 7 to 42. Feed intake (FI), body weight gain (BWG), and feed conversion ratio (FCR) were measured weekly. Utilization of LP did not have a significant effect on the relative weight of internal organs and carcass. The mortality rate was not influenced by treatments. In overall, the FI of birds receiving LP was significantly decreased, while BWG was considerably increased as compared to the control group. Consequently, overall FCR was dramatically improved. تفاصيل المقالة